Several noninfectious pulmonary complications can be associated with chronic graft versus host disease (GVHD). Obstructive airway disease can be a clinical feature of chronic GVHD and the histopathology reveals characteristic lesions of bronchiolitis obliterans. Bronchiolitis obliterans is an obstructive pulmonary disorder affecting the small airways, and it was first described as a late complication of allogeneic bone marrow transplantation (BMT). Spontaneous pneumomediastinum and subcutaneous emphysema can occur in the setting of severe bronchiolitis obliterans and only rarely are they the first sign of such disease. We describe here a case of a 27-year old woman who developed recurrent pneumomediastinum and subcutaneous emphysema that were secondary to the bronchiolitis obliterans that complicated chronic GVHD after allogeneic BMT.